The present invention relates generally to the field of extraluminal balloon dissection. More particularly, the present invention relates to vascular methods and apparatus which can used for creating an anatomic working space alongside an elongate structure, such as a vessel or nerve, for example.
In commonly assigned copending application Ser. No. 07/893,988, filed on Jun. 2, 1992, apparatus and methods are disclosed for developing an anatomic working space for laparoscopic procedures using balloon dissection. In commonly assigned copending application Ser. No. 08/570,766, filed on Dec. 12, 1995, further improvements to the apparatus and methods disclosed in application Ser. No. 07/893,988 are disclosed. The disclosure of each of these prior applications is hereby incorporated by reference in its entirety. The apparatus and methods disclosed in the referenced prior applications include balloon dissection apparatus with relatively large surface balloons which expand laterally and are not particularly well suited for surgical procedures on elongate structures. There is therefore a need for new and improved balloon dissection apparatus and associated methods of use for dissecting or creating space alongside elongate structures in the body.
The present invention provides balloon dissection apparatus and methods of use in which an elongate balloon is utilized to dissect along a region that follows a naturally existing path alongside a vessel or structure, such as an artery, a vein, a lymphatic vessel, the trachea, the esophagus, or even a nerve bundle.
The balloon dissection apparatus for use in extraluminal balloon dissection as described herein may utilize an elongate balloon with a tunneling shaft assembly of the types described in any one of copending U.S. application Ser. Nos. 07/893,988, 08/124,283, 08/267,488, 08/388,233, 08/403,012, or 08/570,766, the disclosure of each of which is hereby incorporated by reference in its entirety. U.S. Pat. No. 4,271,839 to Fogarty et al. which discloses a balloon catheter with an inverted balloon is also expressly incorporated by reference herein.
In a preferred embodiment, the deflated elongate balloon has at least a part of its distal extremity folded inwardly to shorten its predeployment length. The distal portion of the elongate balloon may be inverted into the proximal portion and folded inwardly to provide a balloon having a folded length of roughly one-half the length of the fully distended balloon. Additional inward folds may be provided to further shorten the balloon.
In another preferred embodiment, a thumb-shaped balloon reservoir may be provided as an integral portion of the elongate balloon. The balloon reservoir generally remains outside the body and serves to store the distal portion of the inverted, folded balloon prior to deployment. By storing the bulk of the deflated balloon outside of the body in the reservoir a longer balloon can be utilized. Provision is made for laparoscopic observation.
A bi-directionally expanding balloon is also disclosed which is useful when anatomical obstructions would cause a balloon expanding in one direction only to be blocked. The bi-directional balloon may be utilized either with or without the aid of laparoscopic observation.
In a preferred method of performing extraluminal balloon dissection, a deflated and folded elongate balloon is inserted into an incision in the body adjacent the elongate structure aided by a laparoscope, a finger, or other tunneling member. The folded elongate balloon is then optionally bluntly advanced alongside the elongate structure until a region where it is desired to perform balloon dissection is reached. As the balloon is advanced alongside the elongate structure a laparoscope may be utilized to observe beyond the distal end of the balloon, either from within or alongside the balloon. An inflation medium is then introduced into the balloon to cause the balloon to evert and propagate distally alongside the elongate structure to dissect the structure along a natural tissue plane. The laparoscope may also be use to observe dissection as the balloon propagates alongside the structure if provided. After the structure has been dissected the balloon may be deflated and withdrawn through the incision. The anatomic operating space alongside the vessel created by the dissecting balloon may then be insufflated and a surgical procedure performed.